| Year | 2001 |
| Date | 13-Jul |
| Volume | 187 |
| Issue | 4,150 |
| Page | 14 |
| Category | Internal Combustion |
| Part | 2 |
| Title | I.C. Engine Design |
| Author | David Boote |
| Notes | The Harry Shaw sleeve valve engine. Twin cylinder model SPX engine by Bob Dunn, stepped piston two-strokes, SPX engine |